Electrochemical cells using metal as the fuel are known. A type of electrochemical cell is a metal-air cell, which typically comprises a fuel anode at which metal fuel is oxidized, an air breathing cathode at which oxygen from ambient air is reduced, and an electrolyte for supporting reactions of the oxidized/reduced ions.
In some metal-air cells, such as those disclosed in U.S. patent application Ser. Nos. 12/385,489 and 12/901,410, both of which are incorporated herein by reference, the fuel anode comprises a plurality of scaffolded electrode bodies. Metal fuel is reduced and electrodeposited on the electrode bodies. One challenge with this type of design is ensuring that the growth does not prematurely short adjacent electrode bodies together, thus cutting short the opportunity for dense growth between the bodies.
In such scaffolded metal-air cells, manufacturing error, defects, and wear and tear of the air breathing cathode may result in some areas of fuel on the electrode bodies not being oxidized as rapidly as other areas when the cell is in a current generating mode. When such a cell is then placed in a charging mode, these areas of built-up fuel may cause premature formation of electrical connections between the electrode bodies, which may reduce charge capacity, overall cell efficiency, and energy stored in the battery.
Among other things, the present application endeavors to provide an effective and improved way of eliminating the areas of metal fuel from the fuel anode, effectively resetting the fuel anode of the fuel cell to a fresh chargeable condition.